Control system



June 17 -l 924.

W. SYKES CONTROL SYSTEM Filed Jul 'v;

1920 2 Sheeis-Sheet 1 r 1 8 M 1w i M W I ll V U w mwm W MS Q f'ofward bI l I l 6 2 mm 7 m WITNESSES: w

ATTORNEY Patented June 17, 1924.

UNITED- STATES 1,498,134 PATENT OFFICE.

WILFRED SYKES, OF WILKINSBURG, PENNSYLVANIA, AS SIGNOR TO WESTINGHOUSEELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

common SYSTEM.

Application filed July 7 1820. Serial No. 394,550.

T oall whom it may concern:

Be it known that I, Wrnrnnn Shine, a citizen of the United States, and aresident of Wilkinsburg, in the county of Allegheny and State ofPennsylvania, have invented a new and useful Improvement in ControlSystems, of which the following is a specification.

My invention relates to systems of control and it has special relationto control equipments for reversing rolling mills and the like.

At the present time. the passes of the metal in a reversing rolling millare manually controlled in the following manner. The main-rol1motorspeed is initially made sufiiciently low to cause the ste'el'to enterthe rolls very slowly, in order that the 0 erator may be assured thatthe billet is properly alined,and located squarely in the groove in therolls and also for the purpose of avoiding heavy shocks on the mill. Theoperator then actuates his controller to another position to acceleratethe main-roll motor and pass the metal rapidly through the mill. Justbefore the'end of the piece goes through the rolls, the operator againactuates his controller to .slow down the main-roll motor and cause thesteel to leave I the mill slowly. Such procedure requires a skillfuloperator who must very closely watch the work in order to obtainsatisfactory results.

It is the object of my invention, therefore, to render the operation ofa reversing rolling mill more nearly automatic than obtains at thepresent time, :in order to increase the output and decrease the laborcost, while producing more satisfactory operation than is possible underpresent conditions.

Viewed from another angle, the object of my invention is to render thespeed of the main-roll motor dependent upon the.position, or responsiveto the weight, of the metal under treatment, whereby the speed of themotor is automaticall increased as the metal reaches the rolls and isautomatically decreased just as it leaves the roll.

More specifically stated, one object of my invention is to provide atable-roller device which may. for example, be depresseddur ing thepassage of the metal under treatment to close a set of contact members,whereby the main-motor speedis increased.

Other objects of my invention will'become' evident-from the followingdetailed description, takenni conjunction with the accompanyingdrawings, wherein- Figure 1 is a view, in side elevation, of

operation of the various switches that are shown in Fig. 4:; and

Fig. 6 is a diagrammatic view of a modification or extension of myinvention.

Referring to Figs. 1 to 3 of the drawing, the structure here showncomprises a reversing rolling mill 1 having the usual stands orend-supports 2. for the main rolls 3 and 4.- and which is also providedwith the familiar feeding rolls 5 and 6. A plurality of table-rollers 7are located on each side of the main rolls, in accordance with the usualcustom, being driven through the agency of a plurality of bevelgear-wheels 8' which are mounted upon common shafts 9 and 9a for I eachside of the mill. These shafts are driven,- through the agency ofreducing gean trains 10 and 11, by the table-roller motors 12 and 13,respectively.

The main-roll motor or reversing motor 14 is suitably connected to themain rolls, as by a pinion and gear-whee} 1'5. Uonsequently, themovements or passes of a billet 16, or other metal under treatment, maybe controlled, in both direction and speed, by the tabie-roller motorswhen the billet is at some distance from the main rolls and by the mainmotor 14 when the billet actually reaches the main rolls 3 and 4.

In addition to the customary table rollers 7, a novel table-roller 2t;is located preferably close to the feeding roll 5 for a specialspeed-regulating purpose. It will be noted that the roii 20 is normallylocat d in a position slightly higher than that of the tablerollers 7,as clearly shown in Fig. 2. The

roller 20 is journaled or supported, at its ends, in a block or bearingmember 21 which is adapted. to slide vertically within a stationarybracket or pedestal 22, being biased to the illustrated upper orout-of-alinement position by means of a suitable helicalspring 23, thelower end of which rests upon a bracket or arm 24 forming a art 'of, or

suitably secured to, the main rame-work of the table-roller structure.

A plurality ofspaced contact members 25,

member which is suitably supported by, or

fastened to, the bracket arm 24.

Consequently, depression of the table-. roller 20, in opposition to theaction of the biasing spring 23, by the traveling billet, or other metalunder treatment, causes the electrical contact of the variousillustrated contact members 25 to 30, inclusive, for control pur ses tobe set forth later.

A similar depressible roller structure 31 is provided upon thevoppositeside of the main I rolls 3 and 4 in a position corresponding to that ofthe other depressible roller 20. It will be understood that thedepressible rollers 20 and 31, which are located on the opposite sidesof the main rolls, respectively correspond to forward and to reverseoperation of'the mill, only one of them being effective for any givendirection of operation.v

Fi 2, in addition to the normal relative location of the various rolls3', 4, 7, 20 and 31, illustrates a slight modification that is necessaryin the customary side-guards that travel across the table-rollers. Theseguards are indicated by the rectangular figures to which the referencecharacters 35 and 36 are applied, and it will be noted that a smallcurved notch or roove 37 is provided in the side-guard 35 ]ust above thedepressible roller 20, while a corresponding groove 38 is provided inthe other side-guard 36 just above the depressible roller 31.Consequently, the normal operation of the side-guards is not interferedwith in any way by reason of the normal out-of-alinement position of thedepressible table-rollers 20 and 31.

Referring to the diagram of Fig. 4, the system here shown comprises amain generator which is connected in permanent series relation with themain or reversing mo-.

tor 14, a constant-potential exciter 52 being provided for energizingthe single shunt field winding 61 of the generator 50 and also a shuntfield winding 63 for the reversing motor 14, while a variable-potentialexr citer 53 is employed to energize a variablepotential field winding62 for the reversing motor 14. i

Aplurality of reversing switches or con tactors 41 and 42 are adapted tobe alternately employed for reversing the direction of current ingenerator field winding 61, and corresponding switches 43 and 44 areutilized for a similar purpose in connection with the motor fieldwinding 62.

A normally open switch or contactor 45 is adapted, when closed, toshort-circuit a portion of a resistor 55 that is included in circuitwith the armature of the constailt-potential exciter 52, while a pair ofnormally closed switches 46 and 47 are adapted to shunt or short-circuita portion of the resistors 56 and 57, respectively, that are con nectedin circuit with the main motor field winding 63 and thevariable-potential exciter armature 53, respectively.

In actual practice, the sin le contactors 45, 46 and 47 will each preerably be replaced by a plurality of rogressively operating switches, inaccordance with a familiar practice. However, for the sake ofsimplicity, the single contactors are shown and will be sufiicient toproperly set forth the principles of my invention.

Forv efl ecting the initial or primary control of the various machines,a master switch 58 is provided, being adapted to assume a plurality ofoperative positions a and b in the direction designated as Forward and aand b in the direction designated as Reversed.

It willbe noted that the various contact ,members that are controlled'bythe depressible rollers 20 and'31 are connected in circuit with theactuating coils forthe resistorvarying switches 45, 46 and 47, assubsequently described in detail;

Assuming that it is desired to efi'ect forwardoperation of the main orreversing motor 14, the table-roller motors 12 and 13 having also beenstarted into operation, the master switch 58 may be actuated to itsinitial position b, for example, corresponding to thepreviously-mentioned automatic adjustable-speed control. If thecontroller is actuated to its position a only, then a permanentlyslow-speed operation will be obtained, irrespective of the position ofthe billet or other metal under treatment, since the contact-closingaction of the depressible roller 20 or 31 does not become effectiveunless the master switch 58 occupies its position b.

Under this condition, one circuit is established from the positiveterminal designated by the character of the constantpotential exciter52, through conductor 65, actuating coil of the switch or contactor 41.conductor 66, and control fingers 67 and 68, which are bridged bycontact segment 69 of minal in question, through conductor 71, ac-

tuating coil of the switch or contactor 43, conductor 72 and controlfinger 73, to the contact segment 69 of the master switch.

The two switches orcontactors 41 and 43 are thus closed, while switches46' and 47 are normally closed, as indicated in the first forwardposition of thesequence chart, Fig.

The closure. of the switch 41 establishes a new circuit from thepositive terminal of the constant-potential exciter 52, throughconductors 74, the entire resistor 55,, since the switch 45 is normallyopened, conductors 7 and 76, lower movable contact member 77 of thecontactor 41, conductor 78, field winding 61 of the generator 50,conductors 7 9 and 80, upper movable contact member 81 of the contactor41, and conductor 82 to the negative terminal of the constant-potentialexciter 52. In this way, the field winding 61 for the generator is builtupto the desired value-and in the proper direction for effecting forwardoperation of the main motor 14. r

Another circuit is concurrently established from the positive conductor74, through con:

ductor 83, normally closed switch 46, a portion of the resistor 56,conductor 84, shunt field winding 63 of the main motor 14 and conductor85, to the negative terminal of the exciter 5 2. The field winding 63 isthus energized at a relatively strong value by reason of theshort-circuit of a large portion of the resistor 56 by the switch 46.

The closure of the contactor 43 establishes a circuit, from the positiveterminal of the variable-potential exciter 53 through.

conductor 86, contactor 47, a portion of the resistor 57, conductors 87and 88, upper movable contact member 89 of the contactor 43, conductors90 and 9,1, field Winding 62 of the main motor 14, conductors 92 and 93,lower movable contact member 94 of the contactor 43 and conductors 95and 96, to the negative terminal ottthe variable-potential exciter 53.The fieldwinding 62 is thus also energized at a relatively strong valueby reason of the short-circuit of a large portion of the resistor 57 bythe contactor 47. v

However, in position 5 of the master switch, if either depressibleroller .is actuated to its lower position, the contactor 45 is closed,while the contactors 46 and 47 are opened, as indicated. These controloperationsoccur follows, be'ag dependent upon the position or i "pensiveto the weight of tin biiiet 16 or ;al tier treatment, as

stereo. by rioz'zrnward movement of the one or the other depressiblerollers or 31. From the pqsitive conductor 74, one new circuit isestabllshedthrough conductor '105, actuating coil of the contactor 45,conductor 106, lower orstationary contact member that is associatedwitlithe depressible roller 20, corresponding upper or movable contact member27, conductors 109 and 110 and control finger 111,.whicl1 is connectedto the contact segment 69 of the master switch 58.

' In this way, the contactor is closed as soon as the billet 16 or othermetal to be treated reaches the depressible roller 20 and actuates it toits lower or circuit-closing position. By reason of the closure of theswitch 45, a portion of the resistor is short-circuited to increase thecurrent in the generator field winding 61 which, in turn, causes theimpression of a higher. voltage upon the armature of the main motor 14.Thus, the main motor will accelerate to a new voltage-balancing speedcorresponding to the increased voltage upon its armature terminals.However, further. speed increases of the main motor 14 are brought aboutby the weakening of the shunt field 62 and 63, as about to be described.1

Another new circuit is established from the positive terminal of theexciter 52 through auxiliary contact member 112 of the switch 45, in itsclosed position, conductor 112a, actuating coil of the contactor 46,conductor 113, stationary contact member 28 and movable contact member25, that are associated with, the depressible roller 20, whence circuitis completed through conductor 109 to the negative terminal, aspreviously traced. The contactor 46 is thus liftedto insert the entireresistor 56 in circuit with the shunt field winding 63 of the mainmotor. The electrical interlocking of the switches 46 and 47 with theswitch 45 prevents loss ofmotor torque by weakening of entireYESlStOF'SZ" in circuit with the va-..

riabie-potentiei field Winding 62 for the main motor 14, thus weakeningthe exciting strength thereof in approximate proportion to the weakeningof the shunt field ing' 63.

Ail

the comic! operatiens gust.

described, namely, the increase in the strength of the generator fieldwinding 61 and the decreases in the exciting values of the motor fieldwindings 62 and 63, tend to ever, the inherent time-element inthe mainmotor 14, before full-speed conditions are actually attained, is such asto bring about the desired speed* approximately just after the front endof the billet has entered the main rolls 3 and 4. It will be appreciatedthat the designot. the motor 14, with regard to the distance betweenthe,.depressible roller 20 and the main rolls 3 and 4, may readily bemade suchas to provide the desired timeelement in the motor operation.

The roller 20 is,' of course, depressed throughout the passage of thebillet 16, thus automatically providing the desired high speed as thebillet passes through the mill. As soon as the rear endot the billetpasses beyond the depressible roller, the roller springs back to itsnormal or contactopening position and, consequently, the switch 45 isopened and the switches 46 and 47 are closed, as illustrated in Fig. 4,causing the motor 14 to slow down to the desired speed approximately atthe time that the rear end of the billet leaves the main rolls 3 and 4.

In this way, control of the main motor erated in the reverse directionin a similar manner to that hereinbe'fore setforth, to

' cause a reverse pass of the metal through the mill.

For example, a circuit is established from the positive conductorthrough actuating coil of the switch 42, conductor 121 and controlfinger 122 to the contact segment 123 of the master switch 58.Furthermore, another circuit is established from the positive conductor71 through the actuating coil of the contactor 44, conductor 124 andcontrol finger 125 to the contact segment 123.

The field winding 61 for the generator 50 and the field winding 62 forthe motor are thus reversed, as will be understood without detailedtracing of the circuits.

Since the control finger 1110: is engaged by the contact segment 123 inposition b of the master switch 58, the conductors 1100, 106, 113 and117 are energized whenever the depressible roller 31 is actuated by thetraveling billet. A plurality of lower or stationary contact members107, 118 and 114, are adapted to engage corresponding movable contactmembers 108, 119 and 115 which correspond to the previouslydescribedmovable contact members 25, 26

and'27. Consequently, the closure of the contactor 45 and the opening ofthe contactors 46 and 47 occur whenever the roller 31 is'depressed toprovide the desired highspeed conditions of the main motor 14 at theproper time, as hereinbefore set forth.

Referring to Fig. 6, the system here shown involves an extension of theautomatic idea previously explained, whereby the operation of the mainmotor may be considered as entirely automatic, since its direction ofrotation is automatically governed in accordance with the direction ofrotation of the table-rollers.

Fig. 6 shows one method of obtaining this type of control, the masterswitch 58 for the main motor 14 and 'a-master switch 7 an acceleratingresistor 132 therefor, a set of reversing contactors or switches 133 to136, inclusive, a plurality of resistor contactors or switches 137 and138, and a line contactor 139.

The motor 12 preferably comprises a commutator-type armature 141,- aseries field winding 142, a commutatingfield winding 143 and a shuntfield winding 144, which is bridged by the familiar field-dischargeresistor 145. p

The direction, as well as the degree of energization of the motor 12, isgoverned by the master switch or controller 128, which may beof anywell-known form. In practice, the master switch 128 usually comprises apair of mechanically-coupled faceplate controllers, assembledback-to-back, for

governing "the operation of the respective table-roller motors 12 and13. However, for the sake of simplicity, a drum controller has beenillustrated having two sections respectively corresponding to the motors12 and 13.

The complete control for the motor 12 only is shown. Since the controlof the corresponding motor 13 i similar in all respects, it is notdeemed necessary to illustrate such circuits. Furthermore, since theparticular type of control of the table-roller motors forms no essentialpart of my present invention. 1 do not deem 1t necessary to describe theoperation thereof in detail. It will be suificient to state that thecontroller 128 comprises a contact segment 147, corre sponding toforward operation of the motor 12, and a contact segment148,-corresponding to reverse operation thereof, these contact membersbeing adapted to engage a plurality of control fingers 14:9 in asuitable sequence, in accordance with a familiar practice.

Corresponding contact segments 150 and,

151 and control fingers '152 are provided for governing the operation ofthe other tableroller motor 13, aswill be understood.

' To ensure the proper co-ordinate operation of the master switches 58and 128 for the main .roller motor and the table-roller motors,respectively, the apparatus is arranged as follows. The switches areequipped with the usual controlling handles 154 and 155. and are furtherprovided with suitable sprockets 157 and 158, for example,

which maybe rigidly attached to the operating shafts'159 and 160 of therespective controllers. around the two sprockets 157 and 158, wherebythe desired concurrent operation of both switches, by moving, forexample, the one handle 155 for the table-roller controller 128, isensured."--

The gear ratio between the two,,controller shafts 1s, of course,determined by the relative size of the sprockets and is preferably suchthat each controller reaches its final position at approximately thesame time.

7 In other words, the operation of the tableemployed in lieu thereof, ifdesired. For

.roll shaft of the plate mill. would be arranged to fall between two ofthe exam le, in the case of plate mills, it might be we 1 to provide aroller that is supported onjan arm which is;mounted upon the up er Thlsro er table rollers so that metal reachingit would lift it up slightlyto make the nepes'sary electrical contacts, in accordance withtheprevious description.

Furthermore, it will be understood that, if desired, more than one stepof automaticallyvaried control may be obtained by providing more thanone depressible roller upon each.

side of the main rollers, whereby different values of field-circuitresistance are cut into or out of circuit, as desired. Consequentl I donot wish to be restricted to the speci c structural details, circuitconnections or ar- A chain 161, or the like, passes rangement ofparts'herein set forth, as various modifications thereof may be elfectedwithin the spirit and scope of my invention. I desire, therefore, thatonly such limitations shall-be imposed as are indicated in the appendedclaims.

I claim as my invention:

'1. In a control system for rolling mills, the combination with a motorfor driving the rolls for rolling the metal under treatment, of meansdependent upon the position of one end of said metal for varying thespeed of said motor.

2. In a control system for rolling mills, the combination with a motorfor driving the rolls for rolling the metal under treatment, of meansengaged by one end of the traveling metal for increasing the motor speedas the metal enters therolls.

3. In a control system for rolling mills, the combination with a motorfor driving the rolls for rolling the metal under treatment, of meansresponsive to, the weight of said metal for increasing-the motor speedasthe metal enters and decreasin the motor speed as the metal leaves thero s.

4:. In a control system forrolling mills,

the combination with a motor for driving the rolls for rolling the metalunder treatment, of a device. adapted to be actuated in oppositedirections asthe respective ends of t e metal approach the mill forvarying the motor spee 5. In' a control system for rolling mills, thecombination with a motor for driving the rolls for rolling the metalunder treatment, of a contact-making device adapted to be depressed andlifted as the respective ends of the metal approach the mill for varyingthe motor speed.

6. ha control syste'i'nfor rolling mills, the combination with a motorfor driving "the rolls for rolling the metal under treatment, of ashiftable table-roller for ing the operation of said motor.

7. In a control system for rolling mills, the combination with a motorfor driving the rolls for rolling the metal under treatment, of adepressible table-roller for ingovern- :creasing the motor speed as themetal enters the rolls. a

8. In a, control system for rolling-mills,

the combination with a motor for driving the rolls for rolling the metalunder treatment, of a .bodily movable table-roller, and a circuit closedupon actuationthereof for governing the motor operation.

9. In a control system for rolling mills,

"the combination with a motor for driving the rolls for rolling themetal under treat ment, of a depressible tablemoller, and a circuitclosed upon actuation thereof for increasin the motor speed.

10. n a control system for rolling mills, the combination with a motorfor driving the rolls for rolling the metal under treatment, of adepressible table-roller for controlling the excitation of said motorand spaced from said rolls such a distance that the time elementrequired for the work to proceed from the depressible roller to therolls'will bes'ufiicient to change the motor speed by a predeterminedamount. I

11. In a control system for rolling mills, the combination With a motorfor driving the rolls for rolling the metal under treatment, of means,engaged by the traveling metal for controlling the operation of saidmotor and spaced from said rolls such a dis- 'tan'ce that the timeelement required for the work to proceed from said means '[Olllle rollswill be suflicient to increase the motor speed by a predeterminedamount.

12. In a control system for rolling mills, the combination with a motorfor driving the rolls for rolling the metal under treatment, said motorhaving a shunt field winding, of a table-roller normally out ofalinement with the remaining table-rollers, and switching means closedby movement of said roller to the alined position for reducing thestrength of said field Winding.

13. In a control system for rolling mills, the combination with a motorfor driving the rolls for rolling the metal under treatment, and atable-roller motor, of means for ensuring "the operation of themainrolls and of the table-rollers in the same direc' tion. and meansdependent upon the position of the metal for varying the operation ofone of said motors.

14. In a control system for rolling mills,

the combination with a motor for driving ment, and a table-roller motor,of a plurality of controllers for governing the respective motors, asingle operating handle for eifecting movement of both controllers tothe re spective final positions, corresponding to slow-speed o ration ofthe main-roll motor, and a de pre'ssible table-roller for increasing themain-roll motor speed as the metal enters the rolls.

In testimony whereof, I have hereunto subscribed my name this 22nd dayof June, 1920.

WILFRED sYKEs,

